Light emitting diode illumination apparatus and heat dissipating method therefor

ABSTRACT

A light emitting diode (LED) illumination apparatus including an illumination module, a heat dissipating unit and a loop heat pipe (LHP) device is provided. The illumination module includes a base and many LEDs. The LEDs are disposed on the base. The LHP device contains working fluid and includes an evaporator, a condenser, a first transmitting pipe and a second transmitting pipe. The evaporator is associated with the base and has an outlet, an inlet and a chamber. The condenser is conformably associated with the heat dissipating unit. The condenser has an inlet and an outlet, wherein at least one part of the condenser stretches in a curved pipe shape along a surface of the heat dissipating unit. The first transmitting pipe communicates the evaporator outlet to the condenser inlet. The second transmitting pipe communicates the condenser outlet to the evaporator inlet.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of a prior application Ser.No. 10/948,151, filed on Sep. 24, 2004. The prior application Ser. No.10/948,151 claims the priority benefit of Taiwan application serial no.92126707, filed on Sep. 26, 2003.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an illumination apparatus and a heatdissipating method therefor. More particularly, the present inventionrelates to a light emitting diode (LED) illumination apparatus and aheat dissipating method therefor.

2. Description of Related Art

Light emitting diode (LED) has many advantages, such as small volume,higher illumination efficiency, energy saving and so on. Especially, thephoto-electrical power conversion efficiency of the light emitting diodehas been rapidly improved during the last twenty years, thus the lightemitting diode is regarded as the main illumination source in thefuture. For energy conservation, the light emitting diode will certainlyand gradually being substituted for a lot kinds of today's illuminationsources, such as light bulbs.

Today, the light emitting diodes are applied popularly and commonly usedin traffic signal lights, electric broads, flash lights, and so on.Although improving the high-power illuminating technology or quality ofthe light emitting diodes is the future trend and demanded urgently,such as demanded in the application of reading light or protrudinglight, etc., that still exists some technical bottlenecks to overcome.The main bottleneck for the high-power illuminating technology is theinsufficient heat dissipation ability of the traditional illuminationapparatus of light emitting diodes often leads to the light emittingdiodes in a high operational temperature to decrease theirs servicelife, further, even to cause them to burn down.

As a high-power or high-brightness LED illumination apparatus concerned,such as above 30˜100 W (watt), it is hard to design an effective heatdissipation means for the LED illumination apparatus without fans. Atraditional method of solving the heat dissipation problem is adapting aplurality of cooling fins attached on a base of the illuminationapparatus and the heat generated from the light emitting diodes isconducted to the cooling fins via the base, then using an electric fanto blow the heat away, and thereby the heat is dissipated away. As theabove-mentioned descriptions, the traditional method of heat dissipationusually requires a large space for setting up the plurality of coolingfins near the illumination apparatus and further needs to install anelectric fan, that causes noise and reliability problems when it wasused outdoors.

Another method of heat dissipation is adapting a conventional heat pipedevice, however, the heat dissipation ability is limited due to therigidity of the conventional heat pipe device and the limited length ofconventional heat pipe device, usually can not be longer than 30 cm. Theheat dissipation ability of a conventional heat pipe device is thusmostly less than 30 W. Therefore, the other traditional method also cannot solve the heat dissipation problem of the high-power LEDillumination apparatus effectively.

SUMMARY OF THE INVENTION

The present invention is directed to a heat dissipating method for anLED illumination apparatus. The heat dissipating method dissipates theheat generated by the LED illumination apparatus away efficiently.

The present invention is further directed to an LED illuminationapparatus with better heat dissipating characteristics.

A heat dissipating method for an LED illumination apparatus is provided.The heat dissipating method comprises following steps: using a loop heatpipe (LHP) device to associate an illumination module of the LEDillumination apparatus and a heat dissipating unit of the LEDillumination apparatus, and transmitting the heat generated from theLEDs to the heat dissipating unit via the LHP device. The LHP devicecontains working fluid therein and has a condenser and an evaporator.The condenser communicates with the evaporator. The illumination modulehas a base with a plurality of LEDs thereon. The evaporator isassociated with the base. The condenser is comformably associated withthe heat dissipating unit. At least one part of the condenser stretchesin a curved pipe shape along a surface of the heat dissipating unit inorder to utilize said surface of heat dissipating unit for dissipatingheat.

According to an embodiment of the present invention, the state of theworking fluid in the evaporator may be converted from the liquid stateinto the vapor state by means of absorbing the heat generated from theLEDs. The working fluid at the vapor state in the evaporator may betransmitted to the condenser. The heat of the vapor in the condenser maybe dissipated via the heat dissipating unit to convert the state of theworking fluid from the vapor state into the liquid state. The workingfluid at the liquid state in the condenser may be then transmitted backto the evaporator. In addition, transmitting the working fluid from theevaporator to the condenser and transmitting the working fluid from thecondenser back to the evaporator are accomplished by the capillarityeffect of a porous member mounted in the evaporator.

According to an embodiment of the present invention, the heat generatedfrom the LEDs may be conducted to the evaporator via the base. Inaddition, the base may be also associated with the heat dissipatingunit, and the heat generated from the LEDs may be also conducted fromthe base to the heat dissipating unit directly.

According to an embodiment of the present invention, the heatdissipating method may further comprise using an electric fan disposedbeside the condenser and/or the heat dissipating unit to help dissipatethe heat away.

According to an embodiment of the present invention, the step ofassociating the LHP device with the illumination module may compriseadhering at least one part of the condenser to a surface of the heatdissipating unit with an adhesive or welding at least one part of thecondenser on a surface of the heat dissipating unit.

According to an embodiment of the present invention, the step ofassociating the LHP device with the illumination module may compriseusing a connector to connect at least one part of the condenser and asurface of the heat dissipating unit. The connector has a recess, andthe part of the condenser is pressed into the recess.

An LED illumination apparatus is also provided. The LED illuminationapparatus comprises an illumination module, a heat dissipating unit andan LHP device. The illumination module comprises a base and a pluralityof LEDs. The LEDs are disposed on the base. The LHP device containsworking fluid therein and comprises an evaporator, a condenser, a firsttransmitting pipe and a second transmitting pipe. The evaporator isassociated with the base and has an outlet, an inlet, a chamber and aporous member disposed in the chamber. The chamber may contain theworking fluid at the liquid state therein. The condenser is conformablyassociated with the heat dissipating unit. The condenser has an inletand an outlet. At least one part of the condenser stretches in a curvedpipe shape along a surface of the heat dissipating unit in order toutilize said surface of heat dissipating unit for dissipating heat. Oneterminal of the first transmitting pipe communicates with the outlet ofthe evaporator, and the other terminal of the first transmitting pipecommunicates with the inlet of the condenser. One terminal of the secondtransmitting pipe communicates with the outlet of the condenser, and theother terminal of the second transmitting pipe communicates with theinlet of the evaporator.

According to an embodiment of the present invention, the heatdissipating unit may be a housing of the illumination module. Inaddition, at least parts of the condenser may stretch in a curved pipeshape along the interior surface and/or the exterior surface of thehousing. Besides, at least parts of the condenser may stretch in azigzag shape along the interior surface and/or the exterior surface ofthe housing.

According to an embodiment of the present invention, the heatdissipating unit may be a cooling plate or a lampshade.

According to an embodiment of the present invention, the base may alsobe associated with the heat dissipating unit.

According to an embodiment of the present invention, the porous memberhas a hollow space therein. The working fluid at the liquid state isenveloped in the hollow space by the porous member, and the porousmember is suitable for being permeated with the working fluid.

According to an embodiment of the present invention, the working fluidmay be selected from a group consisting of water, acetone, ammonia andrefrigerant.

According to an embodiment of the present invention, the condenser maycomprise at least one capillary pipe.

According to an embodiment of the present invention, the condenser maybe integrated with the heat dissipating unit for forming a unity member.

According to an embodiment of the present invention, the base maycomprise a circuit board and a conducting unit. The LEDs are disposed onthe circuit board. The conducting unit is associated between the circuitboard and the evaporator. In addition, the conducting unit may be a flatheat pipe or made of ceramic material, polymeric material or metal.

According to an embodiment of the present invention, the base may have acontaining room in which the evaporator is wedged.

According to an embodiment of the present invention, the base maycomprise a circuit board, a clamping block and a conducting unit. TheLEDs are disposed on said circuit board. The clamping block clamps theevaporator. The conducting unit is associated between the circuit boardand the clamping block. In addition, the clamping block has a containingroom in which the evaporator is wedged or a recess in which saidevaporator is wedged.

According to an embodiment of the present invention, the base is acircuit board, for example.

According to an embodiment of the present invention, at least one partof the condenser may be adhered to a surface of the heat dissipatingunit with an adhesive or welded on the surface of the heat dissipatingunit.

According to an embodiment of the present invention, the LEDillumination apparatus may further comprise at least one connectorconnected between at least one part of the condenser and a surface ofthe heat dissipating unit. The connector has a recess, and the part ofthe condenser is disposed in the recess.

According to an embodiment of the present invention, the LEDillumination apparatus may further comprise an electric fan disposedbeside the heat dissipating unit and/or the condenser.

According to an embodiment of the present invention, the insidediameters of the condenser, the first transmitting pipe and the secondtransmitting pipe may be all less than 4 mm, and the total length of thecondenser, the first transmitting pipe and the second transmitting pipemay be longer than 600 mm.

According to the present invention, the heat generated from the LEDs canbe conducted to the heat dissipating unit via the base and the LHPdevice. The LHP device has good heat transmitting properties by usingthe working fluid filled therein to carry the heat generated from theLEDs, such that the LED illumination apparatus in the invention hasbetter heat dissipating characteristics. In addition, by means of usingthe LHP device to associate the illumination module with the heatdissipating unit of the LED illumination apparatus, the heat dissipatingmethod in the invention dissipates the heat generated from the LEDsefficiently.

The above-mentioned contents of the present invention and the followingdescription of the embodiments are only for example, not intended tolimit the scope of the invention. Thus, many equal variations andmodifications of the following embodiments could be made withoutdeparting form the spirit of the present invention and should be coveredby the following claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The objectives, features of the present invention as well as theadvantages thereof can be best understood through the followingembodiments and the accompanying drawings, wherein:

FIG. 1A is a cross-sectional drawing of an LED illumination apparatusaccording to an embodiment of the present invention.

FIG. 1B is a three-dimensional schematic drawing of parts of the LEDillumination in FIG. 1A.

FIG. 1C is a schematic drawing of the LHP device in FIG. 1A.

FIG. 1D is a schematic drawing of the cross-section A-A of theevaporator shown in FIG. 1C.

FIG. 2A illustrates an LHP device and a clamping block of an LEDillumination apparatus according to another embodiment of the presentinvention.

FIG. 2B is a schematic cross-sectional drawing of the evaporator in FIG.2A.

FIG. 2C illustrates an LHP device and a clamping block of an LEDillumination apparatus according to yet another embodiment of thepresent invention.

FIG. 3 is the schematic drawing of a LED illumination apparatusaccording to yet another embodiment of the present invention.

FIG. 4 illustrates a base wedged with an evaporator according to stillanother embodiment of the present invention.

FIG. 5A is a schematic drawing of an LED illumination apparatusaccording to yet still another embodiment of the present invention.

FIG. 5B is a three-dimensional schematic drawing of the connector inFIG. 5A.

DESCRIPTION OF THE EMBODIMENTS

The invention will be explained in detail in accordance with theaccompanying drawings. It is necessary to illustrate that the drawingsin the below could be in simplified forms and not drawn in proportion tothe real cases. Further, the dimensions of the drawings are enlarged forexplaining and understanding more clearly.

An LHP device has many kinds of characteristics or advantages, forexample, the high heat transmitting rate, the far distanceheat-transmitting property, the flexibility property, thenon-directional property (not influenced by the gravity) and theunidirectional heat-transferring property. Besides, the diameter of theconnecting pipe of the LHP device may be less than 4 mm. Therefore, itis very appropriate to use the LHP device to solve the heat dissipationproblem for a LED illumination apparatus with high power or highbrightness.

In an LED illumination apparatus according to an embodiment of thepresent invention, an evaporator of the LHP device is associated withthe LEDs through a base, and a condenser of the LHP device is associatedwith a heat dissipating unit. Therefore, the heat generated from theLEDs can be transmitted to the heat dissipating unit via the LHP device,and then dissipated away from the surface of the heat dissipating unitto make the LED illumination apparatus have better heat dissipatingcharacteristics, such that the lifetime of the illumination apparatus ofthe present invention is increased.

FIG. 1A is a cross-sectional drawing of an LED illumination apparatusaccording to an embodiment of the present invention. FIG. 1B is athree-dimensional schematic drawing of parts of the LED illumination inFIG. 1A. FIG. 1C is a schematic drawing of the LHP device in FIG. 1A.FIG. 1D is a schematic drawing of the cross-section A-A of theevaporator shown in FIG. 1C. Referring to FIGS. 1A to 1D, the LEDillumination apparatus 100 comprises an illumination module 110, a heatdissipating unit 120 and an LHP device 130. The illumination module 110comprises a base 114 and a plurality of LEDs 112. The LEDs 112 aredisposed on the base 114. The LHP device 130 contains working fluid 135therein. The working fluid 135 may be selected from a group consistingof water, acetone, ammonia and other refrigerants. The LHP device 130comprises an evaporator 132, a condenser 134, a first transmitting pipe136 and a second transmitting pipe 138. The evaporator 132 is associatedwith the base 114 and has an outlet 132 a, an inlet 132 b and a chamber132 c. The chamber 132 c may contain the working fluid 135′ at theliquid state therein. The condenser 134 is conformably associated withthe heat dissipating unit 120. The condenser 134 has an inlet 134 a andan outlet 134 b. At least one part of the condenser 134, as shown inFIG. 1B, stretches in a curved pipe shape along a surface of the heatdissipating unit 120 in order to utilize the surface of heat dissipatingunit 120 for dissipating heat. One terminal of the first transmittingpipe 136 communicates with the outlet 132 a of the evaporator 132, andthe other terminal of the first transmitting pipe 136 communicates withthe inlet 134 a of the condenser 134. One terminal of the secondtransmitting pipe 138 communicates with the outlet 134 b of thecondenser 134, and the other terminal of the second transmitting pipe138 communicates with the inlet 132 b of the evaporator 132. The heatgenerated from the LEDs 112 can be transmitted to the heat dissipatingunit 120 via the base 114 and the LHP device 130.

In this embodiment, the evaporator 132 may comprise a porous member 132d in the chamber 132 c. The porous member 132 d has a hollow space 132 etherein. The working fluid 135′ at the liquid state is enveloped in thehollow space 132 e by the porous member 132 d, and the porous member 132d is suitable for being permeated with the working fluid 135. Morespecifically, the body of the evaporator 132 may be a hollow metalcylinder shell 102 with a chamber 132 c therein, and a plurality ofradial protruding members 104 may extend from the metal cylinder shell102 to the inner of the metal cylinder shell 102. The porous member 132d with the hollow space 132 e may be attached within the metal cylindershell 102 to form a plurality of vapor channels 105 between the metalcylinder shell 102 and the porous member 132 d. The hollow space 132 emay be a hollow cylinder chamber filled with the working fluid 135′ atthe liquid state. Due to the capillary effect, the work fluid 135 canpermeate through the porous member 132 d into the vapor channels 105.

In this embodiment, the heat dissipating unit 120 may be a housing ofthe illumination module 110. In addition, at least parts of thecondenser 134 may stretch in a curved pipe shape along the interiorsurface 122 of the heat dissipating unit 120. More specifically, atleast parts of the condenser 134 may stretch in a zigzag shape along theinterior surface 122 of the heat dissipating unit 120. Because thehousing has surfaces with large area, the heat can be dissipated fromthe housing away quickly.

However, it is not confined in the present invention that the condenser134 stretches along the interior surface 122 of the heat dissipatingunit 120. In other embodiments, the condenser 134 may stretch along theexterior surface of the heat dissipating unit 120 or both the exteriorand interior surfaces. Moreover, in other embodiments, the condenser 134may also pass through the heat dissipating unit 120. Besides, the heatdissipating unit 120 may be a cooling plate, a lampshade disposed aroundthe LEDs 112 to reflect the light emitted from the LED 112 or otherobjects with large surface and better heat conductivity, wherein atleast parts of the condenser 134 may stretch in a curved pipe shapealong the exterior surface and/or the interior surface of the lampshade.Moreover, at least parts of the condenser 134 may also stretch in azigzag shape along the exterior surface and/or the interior surface ofthe lampshade.

In this embodiment, the condenser 134 may comprise at least onecapillary pipe. Besides, at least one part of the condenser 134 may beadhered to the surface of the heat dissipating unit 120 with an adhesiveor welded on the surface of the heat dissipating unit 120. In otherembodiments, the condenser 134 may also be integrated with the heatdissipating unit for forming a unity member.

In this embodiment, the base 114 may comprise a circuit board 114 a anda conducting unit 114 b. The LEDs 112 are disposed on the circuit board114 a. The conducting unit 114 b is associated between the circuit board114 a and the evaporator 132. The conducting unit 114 b may be a flatheat pipe, a metal board or other objects with better heat conductivityfor example. The material of conducting unit 114 b may comprise ceramicmaterial, polymeric material or metal. The base 114 may also beassociated with the heat dissipating unit 120, such that the heatgenerated from the LED 112 may also be conducted from the base 114 tothe heat dissipating unit 120 directly. However, in other embodiments,the base 114 and the heat dissipating unit 120 may also be disposedseparately.

A heat dissipating method according to an embodiment of the presentinvention is suitable for being applied to the LED illuminationapparatus 100 as shown in FIG. 1A. The heat dissipating method comprisesthe steps of: using the LHP device 130 to associate the illuminationmodule 110 and the heat dissipating unit 120, and transmitting the heatgenerated from the LEDs 112 to the heat dissipating unit 120 via the LHPdevice 130.

When the LHP device 130 is transmitting heat, the phenomena occur asmentioned below. In this embodiment, the heat generated from the LEDs112 may be conducted to the evaporator 132 via the base 114. Inaddition, the state of the working fluid 135 in the evaporator 132 maybe converted from the liquid state into the vapor state by means ofabsorbing the heat generated from the LEDs 112. More specifically, theheat may be conducted to the metal cylinder shell 102 of the evaporator132 and then conducted to the porous member 132 d via the radialprotruding members 104. Subsequently, the heat is conducted from theporous member 132 to the working fluid 135′ at the liquid state andabsorbed thereby. The working fluid 135″ at the vapor state may thenpermeate through the porous member 132 by the capillarity effect and betransmitted from the evaporator 132 to the condenser 134 by the firsttransmitting pipe 136. The heat of the working fluid 135″ at the vaporstate in the condenser 134 may be dissipated to the environment via theheat dissipating unit 120 to convert the state of the working fluid 135from the vapor state into the liquid state. The working fluid 135′ atthe liquid state in the condenser 134 may be then transmitted back tothe evaporator 132 by the second transmitting pipe 138. It should benoted that transmitting the working fluid 135″ at the vapor state fromthe evaporator 132 to the condenser 134 and transmitting the workingfluid 135′ at the liquid state from the condenser 134 back to theevaporator 132 may be accomplished by the capillarity effect of theporous member 132 d mounted in the evaporator 132.

In the LED illumination apparatus 100 and the heat dissipating methodaccording to the above embodiments of the present invention, because theLHP device 130 has good heat transmitting properties as mentioned aboveto carry the heat generated from the LEDs 112 efficiently, the LEDillumination apparatus 100 in the embodiment has higher heat dissipatingefficiency, and the heat dissipating method dissipates the heat from theLED illumination apparatus 100 efficiently. Therefore, the lifetime ofthe LEDs in the LED illumination apparatus 100 is increased. Inaddition, because of the characteristics and advantages of the LHPdevice as mentioned above, the LED illumination apparatus 100 also hasthe advantages that the illumination module 110 can be disposed far awayfrom the heat dissipating unit 120 to improve the design flexibility ofthe LED illumination apparatus 100, and the LED illumination apparatus100 can be rotated to any orientation without being affected by thegravity. Besides, an electric fan may not be necessary for the LEDillumination apparatus 100 because of the high heat transmittingefficiency of the LHP device 130, such that the size of the LEDillumination 100 can be reduced.

In the LED illumination 100 according to this embodiment, an electricfan may be disposed beside the heat dissipating unit 120, such that theheat can be dissipated from the heat dissipating unit 120 more rapidly.In other embodiments, the electric fan may also be disposed beside thecondenser 134. In this embodiment, the inside diameters of the condenser134, the first transmitting pipe 136 and the second transmitting pipe138 may be all less than 4 mm, and the total length of the condenser134, the first transmitting pipe 136 and the second transmitting pipe138 may be longer than 600 mm, demonstrating the high design flexibilityfor the LHP device 130 in the LED illumination apparatus 100.

FIG. 2A illustrates an LHP device of a LED illumination apparatusaccording to another embodiment of the present invention, and FIG. 2B isa schematic cross-sectional drawing of the evaporator in FIG. 2A.Referring to FIGS. 2A and 2B, an LHP device 130′ is similar to the LHPdevice 130 as shown in FIG. 1A, and the difference between the two ismentioned below. Compared with the structure in FIG. 1D, an evaporator132′ has no radial protruding members 104 as shown in FIG. 1D. Instead,in the evaporator 132′, a porous member 132 d′ is attached to a shell102′ directly. Besides, the porous member 132 d′ has a plurality ofrecesses 132 f in its exterior surface to form vapor channels 105. Inthis embodiment, the heat will be conducted to the shell 102′ of theevaporator 132′ and then conducted to the porous member 132 d′ withoutpassing through the radial protruding members 104 as shown in FIG. 1D.In addition, the evaporator 132′ may be clamped by a clamping block 114c, and the clamping block is associated with the conducting unit. Inthis embodiment, the clamping block 114 c may have a containing room 114c′ in which the evaporator 132′ is wedged. The clamping block 114 c mayalso be applied in the structure of the LED illumination apparatus 100as shown in FIG. 1A to associate the conducting unit 114 b with theevaporator 132. Referring to FIG. 2C, in yet another embodiment, aclamping block 114 d may have a recess 114 d′ to replace the containingroom 114 c′, and the evaporator 132′ is wedged in the recess 114 d′.

FIG. 3 is the schematic drawing of a LED illumination apparatusaccording to yet another embodiment of the present invention. Referringto FIG. 3, an LED illumination apparatus 100′ in this embodiment issimilar to the LED illumination apparatus 100 as shown in FIG. 1A, andthe difference between the two is mentioned below. In this embodiment, abase 114′ is a circuit board associated with the evaporator directly. Inother embodiments, the base may be made of metal or other materials withbetter heat conductivity.

FIG. 4 illustrates a base wedged with an evaporator according to stillanother embodiment of the present invention. Referring to FIG. 4, a base114″ in this embodiment is different from the base 114′ as shown in FIG.3. In this embodiment, the base 114″ may have a containing room 114 c inwhich the evaporator 132 is wedged. Besides, it is not confined in thepresent invention that the LED 112 is disposed on only one surface ofthe base. In this embodiment, the LED 112 may be disposed on multiplesurfaces of the base 114″. In other embodiments, a conducting unit mayhave a containing room or a recess in which the evaporator is wedged.

FIG. 5A is a schematic drawing of a LED illumination apparatus accordingto another embodiment of the present invention, and FIG. 5B is athree-dimensional schematic drawing of the connector in FIG. 5A.Referring to FIGS. 5A and 5B, an LED illumination apparatus 100″ in thisembodiment is similar to the LED illumination apparatus 100 as shown inFIG. 1A, and the difference between the two is mentioned below. In thisembodiment, the LED illumination apparatus 100″ further comprises atleast one connector 140 connected between at least one part of thecondenser 134 and a surface of the heat dissipating unit 120. Theconnector 140 has a recess 142, and the part of the condenser 134 isdisposed in the recess 142. A heat dissipating method according anotherembodiment of the present invention may also comprise the step of usingthe connector 140 to connect the part of the condenser 134 and thesurface of the heat dissipating unit 120, wherein the condenser 134 ispressed into the recess 140 to fit the shape of the recess 140. Becausethe connector 140 can contact the condenser 134 and the heat dissipatingunit 120 tightly, the heat transmitting efficiency from the condenser134 to the heat dissipating unit 120 can be improved.

It should be noted that the heat dissipating method according to FIG. 1Acan also be applied to the LED illumination apparatuses according to theother embodiments mentioned above.

In view of the foregoing, because the LHP device has high heattransmitting rate, the LED illumination apparatus in the invention hasbetter heat dissipating efficiency, and the heat dissipating methoddissipates the heat from the LED illumination apparatus efficiently.Therefore, the lifetime of the LEDs in the LED illumination apparatus isincreased. In addition, because of the characteristics and advantages ofthe LHP device such as the far distance heat-transmitting property, theflexibility property, the non-directional property and theunidirectional heat-transferring property, the LED illuminationapparatus in the invention also has the advantages that the illuminationmodule can be disposed far away from the heat dissipating unit toimprove the design flexibility of the LED illumination apparatus, andthe LED illumination apparatus can be rotated to any orientation withoutbeing affected by the gravity. Besides, an electric fan may not benecessary for the LED illumination apparatus because of the high heattransmitting efficiency of the LHP device, such that the size of the LEDillumination can be reduced.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the structure of the presentinvention without departing from the scope or spirit of the invention.In view of the foregoing, it is intended that the present inventioncover modifications and variations of this invention provided they fallwithin the scope of the following claims and their equivalents.

1. A heat dissipating method for a light emitting diode (LED)illumination apparatus, comprising: using a loop heat pipe (LHP) deviceto associate an illumination module of said LED illumination apparatuswith a heat dissipating unit of said LED illumination apparatus, whereinsaid LHP device contains working fluid therein and has a condenser andan evaporator, said condenser communicates with said evaporator, saidillumination module has a base with a plurality of LEDs thereon, saidevaporator is associated with said base, said condenser is conformablyassociated with said heat dissipating unit, and at least one part ofsaid condenser stretches in a curved pipe shape along a surface of saidheat dissipating unit in order to utilize said surface of heatdissipating unit for dissipating heat; and transmitting the heatgenerated from said LEDs to said heat dissipating unit via said LHPdevice.
 2. The heat dissipating method according to claim 1, wherein thestate of said working fluid in said evaporator is converted from theliquid state into the vapor state by means of absorbing said heatgenerated from said LEDs, said working fluid at the vapor state in saidevaporator is transmitted to said condenser, the heat of said workingfluid at the vapor state in said condenser is dissipated via said heatdissipating unit to convert the state of said working fluid from thevapor state into the liquid state, and said working fluid at the liquidstate in said condenser is then transmitted back to said evaporator. 3.The heat dissipating method according to claim 2, wherein transmittingsaid working fluid from said evaporator to said condenser andtransmitting said working fluid from said condenser back to saidevaporator are accomplished by the capillarity effect of a porous membermounted in said evaporator.
 4. The heat dissipating method according toclaim 1, wherein said heat generated from said LEDs is conducted to saidevaporator via said base.
 5. The heat dissipating method according toclaim 4, wherein said base is also associated with said heat dissipatingunit, and said heat generated from said LEDs is also conducted from saidbase to said heat dissipating unit directly.
 6. The heat dissipatingmethod according to claim 1, further comprising using an electric fandisposed beside said condenser and/or said heat dissipating unit to helpdissipate said heat away.
 7. The heat dissipating method according toclaim 1, wherein the step of associating said LHP device with saidillumination module comprises adhering at least one part of saidcondenser to a surface of said heat dissipating unit with an adhesive orwelding at least one part of said condenser on a surface of said heatdissipating unit.
 8. The heat dissipating method according to claim 1,wherein the step of associating said LHP device with said illuminationmodule comprises using a connector to connect at least one part of saidcondenser and a surface of said heat dissipating unit, said connectorhas a recess, and said part of said condenser is pressed into saidrecess.
 9. An LED illumination apparatus, comprising: an illuminationmodule, comprising: a base; and a plurality of LEDs, disposed on saidbase; a heat dissipating unit; and an LHP device, containing workingfluid therein, said LHP device comprising: an evaporator, associatedwith said base, said evaporator having an outlet, an inlet, a chamberand a porous member disposed in said chamber; a condenser, conformablyassociated with said heat dissipating unit, said condenser having aninlet and an outlet, wherein at least one part of said condenserstretches in a curved pipe shape along a surface of said heatdissipating unit in order to utilize said surface of heat dissipatingunit for dissipating heat; a first transmitting pipe, wherein oneterminal of said first transmitting pipe communicates with said outletof said evaporator, and the other terminal of said first transmittingpipe communicates with said inlet of said condenser; and a secondtransmitting pipe, wherein one terminal of said second transmitting pipecommunicates with said outlet of said condenser, and the other terminalof said second transmitting pipe communicates with said inlet of saidevaporator.
 10. The LED illumination apparatus according to claim 9,wherein said heat dissipating unit is a housing of said illuminationmodule.
 11. The LED illumination apparatus according to claim 10,wherein at least parts of said condenser stretch in a curved pipe shapealong the interior surface and/or the exterior surface of said housing.12. The LED illumination apparatus according to claim 11, wherein atleast parts of said condenser stretch in a zigzag shape along saidinterior surface and/or said exterior surface of said housing.
 13. TheLED illumination apparatus according to claim 9, wherein said heatdissipating unit is a cooling plate or a lampshade.
 14. The LEDillumination apparatus according to claim 9, wherein said base is alsoassociated with said heat dissipating unit.
 15. The LED illuminationapparatus according to claim 9, wherein said porous member has a hollowspace therein, said working fluid at the liquid state is enveloped insaid hollow space by said porous member, and said porous member issuitable for being permeated with said working fluid.
 16. The LEDillumination apparatus according to claim 9, wherein said working fluidis selected from a group consisting of water, acetone, ammonia andrefrigerant.
 17. The LED illumination apparatus according to claim 9,wherein said condenser comprises at least one capillary pipe.
 18. TheLED illumination apparatus according to claim 9, wherein said condenseris integrated with said heat dissipating unit for forming a unitymember.
 19. The LED illumination apparatus according to claim 9, whereinsaid base comprises: a circuit board, wherein said LEDs are disposed onsaid circuit board; and a conducting unit, associated between saidcircuit board and said evaporator.
 20. The LED illumination apparatusaccording to claim 19, wherein said conducting unit is a flat heat pipeor made of ceramic material, polymeric material or metal.
 21. The LEDillumination apparatus according to claim 9, wherein said base has acontaining room in which said evaporator is wedged.
 22. The LEDillumination apparatus according to claim 9, wherein said basecomprises: a circuit board, wherein said LEDs are disposed on saidcircuit board; a clamping block, clamping said evaporator; and aconducting unit, associated between said circuit board and said clampingblock.
 23. The LED illumination apparatus according to claim 22, whereinsaid clamping block has a containing room in which said evaporator iswedged or a recess in which said evaporator is wedged.
 24. The LEDillumination apparatus according to claim 9, wherein said base is acircuit board.
 25. The LED illumination apparatus according to claim 9,wherein at least one part of said condenser is adhered to a surface ofsaid heat dissipating unit with an adhesive or welded on the surface ofsaid heat dissipating unit.
 26. The LED illumination apparatus accordingto claim 9, further comprising at least one connector connected betweenat least one part of said condenser and a surface of said heatdissipating unit, wherein said connector has a recess, and said part ofsaid condenser is disposed in said recess.
 27. The LED illuminationapparatus according to claim 9, further comprising an electric fandisposed beside said heat dissipating unit and/or said condenser. 28.The LED illumination apparatus according to claim 9, wherein the insidediameters of said condenser, said first transmitting pipe and saidsecond transmitting pipe are all less than 4 mm, and the total length ofsaid condenser, said first transmitting pipe and said secondtransmitting pipe is longer than 600 mm.